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authorSteve Chamberlain <sac@cygnus>1993-04-27 01:17:32 +0000
committerSteve Chamberlain <sac@cygnus>1993-04-27 01:17:32 +0000
commit9faacb925f0b526a5c79c886c711f2826e1ecbb7 (patch)
tree06caa461dc95129a7b0918846d05c7bfbba0278b /gdb/sh-tdep.c
parented173a7696deb9417b59db73e105bfae8a17ab7a (diff)
downloadppe42-binutils-9faacb925f0b526a5c79c886c711f2826e1ecbb7.tar.gz
ppe42-binutils-9faacb925f0b526a5c79c886c711f2826e1ecbb7.zip
Support for Hitachi SH
Diffstat (limited to 'gdb/sh-tdep.c')
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diff --git a/gdb/sh-tdep.c b/gdb/sh-tdep.c
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+/* Target-machine dependent code for Hitachi Super-H, for GDB.
+ Copyright (C) 1993 Free Software Foundation, Inc.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+/*
+ Contributed by Steve Chamberlain
+ sac@cygnus.com
+ */
+
+#include "defs.h"
+#include "frame.h"
+#include "obstack.h"
+#include "symtab.h"
+#include "gdbtypes.h"
+#include "gdbcmd.h"
+#include "value.h"
+#include "dis-asm.h"
+#include "../opcodes/sh-opc.h"
+
+
+/* Prologue looks like
+ [mov.l <regs>,@-r15]...
+ [sts.l pr,@-r15]
+ [mov.l r14,@-r15]
+ [mov r15,r14]
+*/
+
+#define IS_STS(x) ((x) == 0x4f22)
+#define IS_PUSH(x) (((x) & 0xff0f) == 0x2f06)
+#define GET_PUSHED_REG(x) (((x) >> 4) & 0xf)
+#define IS_MOV_SP_FP(x) ((x) == 0x6ef3)
+#define IS_ADD_SP(x) (((x) & 0xff00) == 0x7f00)
+
+
+/* Skip any prologue before the guts of a function */
+
+CORE_ADDR
+sh_skip_prologue (start_pc)
+ CORE_ADDR start_pc;
+
+{
+ int w;
+
+ w = read_memory_integer (start_pc, 2);
+ while (IS_STS (w)
+ || IS_PUSH (w)
+ || IS_MOV_SP_FP (w))
+ {
+ start_pc += 2;
+ w = read_memory_integer (start_pc, 2);
+ }
+
+ return start_pc;
+}
+
+/* Disassemble an instruction */
+
+int
+print_insn (memaddr, stream)
+ CORE_ADDR memaddr;
+ FILE *stream;
+{
+ disassemble_info info;
+ GDB_INIT_DISASSEMBLE_INFO (info, stream);
+ return print_insn_sh (memaddr, &info);
+}
+
+/* Given a GDB frame, determine the address of the calling function's frame.
+ This will be used to create a new GDB frame struct, and then
+ INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
+
+ For us, the frame address is its stack pointer value, so we look up
+ the function prologue to determine the caller's sp value, and return it. */
+
+FRAME_ADDR
+sh_frame_chain (thisframe)
+ FRAME thisframe;
+{
+ if (!inside_entry_file (thisframe->pc))
+ return (read_memory_integer (FRAME_FP (thisframe), 4));
+ else
+ return 0;
+}
+
+/* Put here the code to store, into a struct frame_saved_regs,
+ the addresses of the saved registers of frame described by FRAME_INFO.
+ This includes special registers such as pc and fp saved in special
+ ways in the stack frame. sp is even more special:
+ the address we return for it IS the sp for the next frame. */
+
+
+void
+frame_find_saved_regs (fi, fsr)
+ struct frame_info *fi;
+ struct frame_saved_regs *fsr;
+{
+ int where[16];
+ int rn;
+ int have_fp = 0;
+ int depth;
+ int pc;
+ int opc;
+ int insn;
+
+ opc = pc = get_pc_function_start (fi->pc);
+
+ insn = read_memory_integer (pc, 2);
+
+ for (rn = 0; rn < NUM_REGS; rn++)
+ where[rn] = -1;
+
+ depth = 0;
+
+ /* Loop around examining the prologue insns, but give up
+ after 15 of them, since we're getting silly then */
+ while (pc < opc + 15 * 2)
+ {
+ /* See where the registers will be saved to */
+ if (IS_PUSH (insn))
+ {
+ pc += 2;
+ rn = GET_PUSHED_REG (insn);
+ where[rn] = depth;
+ insn = read_memory_integer (pc, 2);
+ depth += 4;
+ }
+ else if (IS_STS (insn))
+ {
+ pc += 2;
+ where[PR_REGNUM] = depth;
+ insn = read_memory_integer (pc, 2);
+ depth += 4;
+ }
+ else if (IS_ADD_SP (insn))
+ {
+ pc += 2;
+ depth += -((char) (insn & 0xff));
+ insn = read_memory_integer (pc, 2);
+ }
+ else break;
+ }
+
+ /* Now we know how deep things are, we can work out their addresses */
+
+ for (rn = 0; rn < NUM_REGS; rn++)
+ {
+ if (where[rn] >= 0)
+ {
+ if (rn == FP_REGNUM)
+ have_fp = 1;
+
+ fsr->regs[rn] = fi->frame - where[rn] + depth - 4;
+ }
+ else
+ {
+ fsr->regs[rn] = 0;
+ }
+ }
+
+ if (have_fp)
+ {
+
+ fsr->regs[SP_REGNUM] = read_memory_integer (fsr->regs[FP_REGNUM], 4);
+ }
+ else
+ {
+ fsr->regs[SP_REGNUM] = fi->frame - 4;
+ }
+
+ /* Remember the address of the frame pointer */
+
+ /* Work out the return pc - either from the saved pr or the pr
+ value */
+
+ if (fsr->regs[PR_REGNUM])
+ {
+ fi->return_pc = read_memory_integer (fsr->regs[PR_REGNUM], 4) + 4;
+ }
+ else
+ {
+ fi->return_pc = read_register (PR_REGNUM) + 4;
+ }
+}
+
+/* initialize the extra info saved in a FRAME */
+
+void
+init_extra_frame_info (fromleaf, fi)
+ int fromleaf;
+ struct frame_info *fi;
+{
+ struct frame_saved_regs dummy;
+ frame_find_saved_regs (fi, &dummy);
+}
+
+
+/* Discard from the stack the innermost frame,
+ restoring all saved registers. */
+
+void
+pop_frame ()
+{
+ register FRAME frame = get_current_frame ();
+ register CORE_ADDR fp;
+ register int regnum;
+ struct frame_saved_regs fsr;
+ struct frame_info *fi;
+
+ fi = get_frame_info (frame);
+ fp = fi->frame;
+ get_frame_saved_regs (fi, &fsr);
+
+ /* Copy regs from where they were saved in the frame */
+ for (regnum = 0; regnum < NUM_REGS; regnum++)
+ {
+ if (fsr.regs[regnum])
+ {
+ write_register (regnum, read_memory_integer (fsr.regs[regnum], 4));
+ }
+ }
+
+ write_register (PC_REGNUM, fi->return_pc);
+ write_register (SP_REGNUM, fp + 4);
+ flush_cached_frames ();
+ set_current_frame (create_new_frame (read_register (FP_REGNUM),
+ read_pc ()));
+}
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